Saturday, September 19, 2009

Previous PATH system variables

After using SETX commands on windows, I have accidentally set my system PATH to empty! The good news is your previous/other system PATH is available from the windows registry.

Simply run "regedit" and go to "HKLM\SYSTEM\ControlSetXXX\Control\Session Manager\Environment\Path" to retrieve the path in previous/other configurations.

Thursday, September 17, 2009

MS Windows' SETX command

I was sick of clicking to control panel > system > advance properties > environment variable just to update the system PATH variable. Fortunately, the new Vista build comes with the command SETX.

To add to the system path, now all I have to do is run the following command in an administrator mode command prompt:
I also think it is available to XP user by downloading Windows XP Service Pack 2 Support Tools

Sunday, September 13, 2009

Freeundelete from

I got in to the bad habit of just doing straight file deletes on windows, skipping the recycling bin all together. To do this, simply hold down the shift key when you press the delete button. Explorer will still prompt you for a confirmation, but anyone who has done this enough times will have their muscle memory take over and hit enter key right after.

Unfortunately, I have done this to one of my pet project which I have been working for a few days now. Pet project also means no SCM, no backup. Lesson learned.

The good old undelete is no longer available from DOS! In a frantic search to recover the files, I came across the "FreeUndelete" tool available from, and it worked like a charm.

Although there are a few corrupted files, most of the files restored without any problems. I hope I don't have to use this tool every again.

Sunday, September 6, 2009

RPX: Aggregating Identity Services as a Service

I recently listen to a podcast by Brian Ellin and Doug Kaye on IT conversation. The topic of the day was a relatively new SaaS offering by JanRain. The service offers the ability to integrating existing authentication and identity services, for example, Facebook, Google, Windows Live, etc. Why ask your user to sign-up for yet another account when user identity is not part of your core business?

There were lots of attempts to contain the proliferation of user name, passwords and online accounts, but none that I know of really took the approach of integrating with existing services and then package it as a service. I think the guys at JanRain is onto something.

Check out RPX by JanRain @

Friday, September 4, 2009

Digital Hardware Project

After some random browsing on the internet, I discovered my digital hardware project is publicly out there on the internet.

I had ambitious dreams back then. I convinced my partner we are going to build a VOIP application on an FPGA using merely the laboratory time in one course. I even manage to secure a $2,000 piece of hardware from Xilinx as well as the expensive programming and simulation software. At the end of the course, we don't have an operational prototype, nonetheless it was a valuable learning experience.

Without further ado, here is the write-up of the project.